Tus&ilago.] XLIII. COMPOSITE. 243 



with a loose, white, cottony wool, of which there is a little also on the 

 upper side. 



In waste and cultivated ground throughout Europe and central and 

 Russian Asia to the Arctic Circle, and a very troublesome weed in poor, 

 stiff soils. Abundant in Britain. Fl. early spring. 



2. T. Petasites, Linn. (fig. 541). wtterbur. Leaves of T. Farfara, 

 but usually larger. Flowering stems not in tufts, often a foot high 

 when full-grown, with many flower-heads, of a dull, pinkish-purple, in 

 a narrow-oblong terminal panicle, and almost dioecious. The .male 

 plant has a looser panicle of smaller heads, the florets either all tubular 

 and male (the pistil, although apparently perfect, having no ovule and 

 forming no seed), or with a few filiform female ones on the outside ; 

 the female panicle more compact, the heads larger, the florets all 

 filiform, or with a few tubular male ones in the centre. Petasites 

 wdgaris, Desf. 



In sandy meadows, on the banks of streams, or roadsides, in Europe 

 and Russian Asia, but not an Arctic plant. Frequent in England and 

 in Ireland, extending into southern Scotland. Fl. spring. It is often 

 distinguished from Tussilago as a genus, under the name of Petasites. 



XX. SENECIO. SENECIO. 



Herbs (or, in some exotic species, shrubs), with alternate, toothed o* 

 divided, rarely entire leaves. Flower-heads in terminal corymbs ; the 

 florets of the disk yellow and tubular, those of the ray also yellow (or, 

 in some exotic species, blue, purple, or white), spreading, or rarely 

 wanting. Involucre cylindrical or nearly hemispherical, with 1 or 2 

 rows of linear bracts of equal length, often tipped with brown, usually, 

 but not always, accompanied by a few small outer bracts at their base. 

 Receptacle without scales. Achenes cylindrical, with a pappus of 

 simple hairs, usually soft and white. Branches of the style truncate 

 at the top, usually with a tuft of minute hairs. 



This, the largest of all Composite genera, is spread over every quarter 

 of the globe, although the majority of species occupy each a small area. 

 Several species which have not the small outer bracts to the involucre 

 were distinguished by Linnaeus under the name of Cineraria, but the 

 character has proved so uncertain that modern botanists have given 

 it up. 



Leaves cut and divided. 

 Floret* of the ray very small and rolled back, or entirely wanting. 



Root annual. 

 Ray none. Flower-heads almost sessile, in dense corymbs 



or clusters 1. 8. vulgarit. 



Ray small and rolled back or rarely wanting. Flower-heads 



stalked, in loose corymbs. 



Whole plant very viscid. Involucres broadly cylindrical, 

 of about 20 bracts, with 2 or 3 short outer ones. Achenes 



glabrous 2. & viicosHt. 



Plant rarely viscid. Involucres narrow, of about 12 to 14 

 bracts; the outer ones scarcely perceptible. Achenes 



silky 3. S. tylvaticut. 



floreti of the ray conspicuout and spreading. [Rarely absent in S. 



Jacobaa.] 

 Root annual. 



Achenes with short silky hairs . , . . . , i. & tqualidui. 

 Achenes quite glabrous , * , . , , , 6, S. aqualicut. 



